1. Field of the Invention
The present invention relates to a manufacturing method of a thin-film magnetic head provided with a magnetoresistive effect (MR) element and to a manufacturing method of a head gimbal assembly (HGA) provided with the thin-film magnetic head.
2. Description of the Related Art
Recently, a high sensitivity magnetic head has been demanded as the increase in the recording density of a hard disk drive (HDD). In order to satisfy such demand, a thin-film MR head provided with a giant magnetoresistive effect (GMR) element utilizing the spin valve effect for example, or a tunnel magnetoresistive effect (TMR) element has been proposed.
Such high sensitivity MR head is extremely vulnerable to electro-static discharge (ESD), and thus if it is fabricated with opened electrode terminals of the MR element, ESD destruction or deterioration in its performance may occur during the manufacturing processes. This tendency has been accelerated when the recording density of the magnetic disk reaches and exceeds a value corresponding to the recording capacity of 80 G bytes per platter.
Japanese patent publication No. 10269534A discloses a method for preventing the ESD destruction or deterioration in the performance of a spin valve MR head by electrically connecting a short circuit between a pair of lead conductors of each MR element formed on a wafer during the wafer process, then cutting the wafer into bar members each of which has magnetic head sliders aligned, and thereafter cutting the short circuit when each of the bar members is cut and separated into individual magnetic head sliders.
However, according to this known method, it is necessary to design each short-circuit pattern so that the patterned short circuit can be surely cut when the bar member is cut and separated into individual magnetic head sliders. The pattern therefore has to be elongated causing the wafer surface to correspondingly occupy. This reduces the effective utilization factor of the wafer surface. Also, according to the known method, the MR element can be prevented from the ESD destruction by short-circuiting only before the bar member is cut and separated into individual magnetic head sliders, and therefore, during fabrication processes after that, another protection scheme is required to prevent the MR element from the ESD destruction.